It seems every author is aware of theme, but try to find one who can define it! Most will tell you theme has something to do with the mood or feel of a story. But how does that differ from genre? Others will say that theme is the message of the story. Some will put forth that theme is the premise of a story that illustrates the results of certain kinds of behavior.
Taking each of these a bit farther, a story’s mood or feel might be “anger”. A message might be “nuclear power plants are bad”. A premise could be “greed leads to self-destruction.” Clearly each of these might show up in the very same story, and each has a somewhat thematic feel to it. But just as certainly, none of them feels complete by itself. This is because each is just a different angle on what theme really is.
In fact, theme is perspective. Perspective is relationship. Theme describes the relationship between what is being looked at and from where it is being seen. This is why theme has traditionally been so hard to describe. It is not an independent thing like plot or character, but is a relationship between plot and character.
As a familiar example, think of the old adage about three blind men trying to describe an elephant. Each is like a character in a story, and their investigation of the beast is like the plot. One, feeling the tail comments, “It is long and thin like a snake.” Another, feeling the ear replies, “No, it is wide and flat like a jungle leaf.” The final investigator feels the leg and retorts, “You are both wrong! It is round and stout like a tree.” How each of those men felt about the elephant, how they understood it, depended upon his point of view, and the fact that it was an elephant. It is also true, that had another animal been the object of study, the perspective would have changed as well.
Where we are looking from are the four points of view represented by the four throughlines (Objective Story, Main Character, Obstacle Character, and Subjective Story). In stories, what we are looking at is the problem that the Story Mind is considering. So, to truly understand perspective (and therefore theme) we must be able to accurately describe the nature of the story’s problem, and then see how its appearance changes when seen from each different point of view.